A wide variety of packages are used to contain and protect a substance until it is desired to release and dispense the substance from the package. Several methods exist for dispensing and applying various solid substances or articles, such as powders, pills, granules and other shaped substances. Said methods may also be used to dispense and apply various flowable substances such as gels, solutions, dispersions, and other dimensionally unstable substances. In some cases, it may be desirable to include structure as part of the package which assists in dispersing or applying the contents. Oftentimes, the package includes an applicator for directed application of the contents, as they are dispensed from the package.
Several factors are taken into consideration in providing a method for dispensing a flowable or solid substance. One concern is the performance characteristics of the dispensing package. For example, the ease with which the package can be opened and its contents expelled can be important. The ability of the package to store and contain a substance prior to its application is another factor. When an applicator such as an absorbent pad or sheet is included as part of the package, secure attachment of the applicator to the packaging can be important so that the applicator does not become disengaged during use.
Various packages have been developed to contain and dispense solutions, dispersions or gels of various active ingredients. One such dispenser is an envelope-like package that defines an internal reservoir for containing a fluid. For example, U.S. Pat. No. 4,427,115 to Laipply, discloses a packaging device for applying various fluids to the skin. The device is made of a flexible sheet of fluid impermeable material that is folded in half and sealed around the edges in a temporary seal. The two halves of the sheet are pulled apart to break the seal and form a flat surface covered with the fluid. An absorbent pad may be adhered inside the chamber to aid in the retention and delivery of the fluid.
Other packaging systems provide for a cup-like reservoir with a foil or paper covering that is torn off to expose the fluid or other material contained within the chamber. For example, Canadian Patent No. 613,023 to Wilson et al. disclose a creamer-type dispenser with a wide-mouthed cup and a covering sheet sealed over the mouth of the cup. The covering sheet has a tab adhesively sealed over a flat extension of the rim of the cup. The package is opened by pulling the tab of the covering sheet upward off the rim extension and inward toward the cup. U.S. Pat. No. 3,860,348 to Doyle et al. disclose a cup with a foil covering over the mouth and a liquid-impregnated sponge attached to the inside of the cup. When the covering is peeled off the rim of the cup, the sponge projects outward through the opening.
U.S. Pat. No. 4,372,098, to Mason discloses an applicator package with a pair of side panels, one of which has a recessed portion for receiving an absorbent pad which is secured to the side panel within the central recessed portion. The applicator means sealed within the package by sealing the edged portion of the side panel in surrounding relation to the applicator means thereby enclosing and hermetically sealing the applicator means within the side panels. One of the edged portions of the side panels is then secured to enable the side panels to be gripped at that area and separated from each other so as to expose the applicator means.
U.S. Pat. No. 4,796,751 to Madkour discloses a portable eyeglass cleaning kit which comprises a generally flat flexible container having two separate compartments which are separably operable to make available the lens cleaning medium and the lens wiping medium. The cleaning and wiping media are sheets of absorbent material such as woven or unwoven fabric or tough liquid absorbent paper. The cleaning and wiping media are not affixed to the container and are separably removable from the compartments of the container. The container is made of a moisture and gas impervious sheet material such as metal foil, treated paper or plastic film. The container is operable by tearing along a scored line or by separation of the sealed edges.
Packages have also been developed to expel the contents of an inner chamber through a fracture or score line in one surface of the package. The ends of the package are forced together to expand and rupture the score line. For example, U.S. Pat. No. 3,968,630 to Redmond discloses a dispensing package having a single reservoir with a pattern of perforations cut partially through the surface on one side of the package that is covered with a foil sealant.
A further consideration in designing a useful dispensing system is the ability to deliver more than one substance from a unitary system. Also desirable is a packaging system that is useful to simultaneously combine and dispense a plurality of substances, each requiring separate storage until being combined, due to their physical or chemical incompatibility.
To accomplish this, several applicator systems with a prescored fracture line in one surface of a package provide for reservoirs in discrete portions of a single package. For example, U.S. Pat. No. 4,140,409 to DeVries discloses a package system for containing and dispensing liquids and other flowable materials comprising a reservoir chamber in each half of an elongated package. A prescored fracture line in one surface of the package ruptures when the ends of the package are urged together, and the contents of the chambers are expelled into an applicator sponge that is attached to the outside of the package. However, a disadvantage of packages with such externally placed applicators is that the applicator may become soiled or detached. Also, where a sterile applicator is desired, such a package system may not maintain the applicator under sanitary conditions prior to use.
A covering maybe provided to enclose an externally attached applicator. For example, U.S. Pat. No. 4,430,013 to Kaufman discloses a package system that has an interior chamber for containing a fluid, a score line in one surface of the package, and an applicator mounted over the score line. An overwrap with a fracture line on one surface encloses the package and the applicator. When the package is folded in half, the score line is broken and the fluid in the reservoir chamber is expelled into the applicator. The applicator then bursts through the fracture line in the overwrap.
In accordance with this packaging system, the liquid substance is contained and stored within a reservoir separately from the applicator until the package is opened. A drawback of this system is that to dispense the substance from the package, the reservoir chamber must first be opened, and the substance must be ejected therefrom and then dispersed into and through the applicator, which can result in uneven wetting of the applicator. In addition, problems may occur because of premature leakage or evaporation of the liquid contents from the inner chamber of the dispensing package into the external applicator due to a premature break in the fracture line. If the overwrap becomes torn or punctured, the applicator may become uncovered and contaminated, and the liquid substance prematurely dispensed.
To provide a more secure containment, the applicator may be enclosed within a more rigid package. Kaufman also discloses a package system in which an applicator is attached to the inside of a package that has a score line on one surface. The applicator is compressible and sponge-like with a protruding thickened portion placed against the score line. A rib projection is provided on the inside surface of the package opposite the score line to help push the applicator out through the score line when the package is folded. A drawback is that the package cannot be reclosed or resealed with the applicator contained inside once the fracture line is separated and the applicator extruded.
U.S. Pat. No. 4,812,067 to Brown et al. also provide a system that provides separate reservoir chambers in a flexible package. The chambers are compressed to rupture an internal seal in the package which urges the liquid contents into a central dispensing cavity. The ends of the package are bent backward to split open a score line in the surface of the package. Pressure on the package forces the contents to be expelled through the slit in the score line and onto a sponge attached to the outside of the package.
A disadvantage of packaging devices that release their contents by rupturing a score line in the container wall is that flexing of the package prior to use may cause the fracture line to split apart prematurely, thus causing unwanted leakage or premature dispersal of the contents. Conversely, the score line may be constructed such that it is difficult to break.
Therefore, there is a need for a method of dispensing system which addresses the above-mentioned problems of prior dispensing systems. In particular, there is a need for a packaging system for dispensing flowable and/or solid substances which has an improved configuration for releasing the contents of the packaging that is not prone to premature rupture, but provides ready dispensing of the package contents. There is also a need for a packaging that is a convenient means of dispensing a plurality of flowable and/or solid substances from multiple chambers within the packaging system, to overcome the physical or chemical incompatibility of the substances, or to allow for sequential application.